Quality control is an important phase in product manufacturing. In factories or manufacturing sites, finished or semi-finished products are often inspected to determine whether the products are produced to meet a set of production requirements. In one example, testing of video rendering devices (e.g., set-top boxes, video cards of computer devices, display cards of mobile phones, portable multimedia devices, video players of various video formats such DVD and Blu-ray players, digital video recorders, etc.) includes testing of the video output of the video devices. The main idea of such a final system level test is to verify that the video being displayed to the user is acceptable with no noticeable impairments while various operations are being performed on the video rendering device.
Typically, the testing of a video rendering device can be performed by connecting a display device (e.g., a monitor or a television) to a video rendering device under test, and test personnel can observe the output as shown on the display device. The test personnel decide if the video device passes or fails the test based on a subjective evaluation of the output shown on the display device. Among other problems, manual testing is time-consuming and subject to human error. For example, sometimes the test is too long such that the tester cannot reliably verify the test. In other cases the error may happen very rarely or is visible to some testers but not others.